Thin-film cells, encapsulation

In addition to the thin-film solar cells, this system is suitable for use in other flexible electronics, such as a flexible, transparent, and light-weight encapsulation of organic light-emitting diode (OLED) displays and lighting. 

It is of interest primarily for very uniform ultra-thin films and coatings (0.002-5 mils) in applications such as electrical resistors, thermistors, thermocouples, stator cores, connectors, fast-sensing probes, photo cells, memory units, dropwise steam condensers for recovery of sea water, pellicles for beam splitters in optical instruments, windows for nuclear radiation counters, panels for micrometeorite detection, dielectric supports for planar capacitors, encapsulation of reactive powders, and supports in x-ray and optical work. Any significant growth would depend upon a major breakthrough in process techniques and a consequent lowering in price. 

The thin cylindrical gel was placed in a sealed glass microcapillary of inner diameter of 1.35 mm. As is illustrated in Fig. 2, the capillary was encapsulated in a transparent cell, within which water was circulated to control the temperature. The glass microcapillary with the thin film gel was directly encapsulated in the cell. The temperature was regulated within + 0.05 °C. On the other hand, the film gel with glass plate was directly encapsulated in the transparent cell shown in Fig. 2. In both cases, the temperature of gels was not directly measured, but was obtained by measuring the difference between the circulated water temperature and the temperature of the places where gels were set in. 

Reliable stability data of the p-i-n solar cell itself are not easily obtained, especially for non-encapsulated cells or modules. One of these tests e.g. for EN/IEC 61646 certification of modules is the so-called damp-heat test (85°C, 85% humidity, up to lOOOh). Recent studies were performed by Stiebig et al. [50, 51] exposing different types of cells to harsh conditions. One of the most important results was the excellent stability of silicon thin film solar cells. Remarkably, this is also valid for small area modules even without encapsulation [52]. This is of high interest because costs and efforts for module encapsulation strongly depend on the inherent stability of the solar cells. As a more detailed treatment of this subject is beyond the scope of this chapter, the reader is referred to the original papers [50,51]. 

Biotemplates have been fabricated from two-dimensional crystalline surface proteins for the subsequent electrochemical deposition of nanowire structures [82]. These surface layer proteins encapsulate certain bacterial cells, controlling extracellular transport. They form especially robust thin films over cells, and are resistant to conditions that normally denature proteins, such as low pH and heat, thus making them ideal as template materials for electrodeposition. Schwartz and coworkers investigated a hexagonally packed intermediate surface layer protein from... 

For example, polymer-coated intravascular stents have been used to localize the delivery of DNA to the vascular wall and could lead to innovative gene-based treatments for vascular diseases or related conditions [30]. Likewise, plasmideluting polymer matrices have been applied to the localized delivery of DNA to cells in the context of tissue engineering [31]. Although degradable polymer matrices can be used to sustain the release of encapsulated DNA, general methods for the localized, efficient, and sequential delivery of DNA from thin films and... 

Apart from polyplexes, various nanoscale assemblies of cationic polysaccharides are also proposed to promote the surface-mediated delivery of DNA to cells. These approaches are classified into one of two broad categories (i) methods based upon the physical adsorption of preformed polyplex on polymeric surfaces like PLGA or collagen films and these polyplex functionalized films promoted surface-mediated transfection of cells in vitro and in vivof (ii) methods for layer-by-layer adsorption of DNA and cationic polymers on surfaces to fabricate multilayered thin films. Recently, degradable carbohydrate-based nanogels were proposed for codelivery of pDNA and therapeutic proteins. These systems were designed to possess stimuli-sensitive characteristics where the temperature-sensitive property of nanogels allowed the facile encapsulation of biomaterials, while... 

Spherical liquid membranes consist, in simplest terms, of an emulsion suspended in a liquid that does not destroy the emulsion. In a typical application, small droplets of aqueous solution are encapsulated in a thin-film oil this emulsion is then suspended in another aqueous solution. Alternatively, small droplets of oil can be emulsified with water and the emulsion suspended in oil. In the first case, the oil phase is the liquid membrane in the second case, the water is the Uquid membrane. A typical droplet might be about 100 p,m in diameter. These spherical liquid membrane systems have many potential medical applications in the emergency treatment of drug overdoses and for oxygenating the blood system. Spherical liquid membranes may be applied in resource recovery and water purification, as encapsulated cells as well as liquid membrane encapsulated enzymes [331). 

A new silicone encapsulant for the solar industry is available that can enable flexible thin-film modules to be laminated cost effectively using roll-to-roll processing. Marketed under the trade name ELASTOSIL Solar 2200, this new product is transparent, pourable and non-corrosive. It vulcanizes rapidly at elevated temperature and reportedly features outstanding adhesive properties. In its cured state, it can provide all types of thin-film solar cells with effective long-term protection from chemical and mechanical stresses. Web www.wacker.com... 

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